Many hair shampoo compositions provide acceptable cleaning but provide little or no styling benefits, e.g., body, hold, stiffness. To realize such benefits, separate cleaning and styling products are often applied to hair prior to, during or after shampooing.
Recently, hair shampoo compositions have been developed which can provide cleaning performance with some styling benefits, all from a single product. Many of these products contain styling polymers in a compatible shampoo base. To prepare such products, styling polymers can be dissolved in an organic solvent and then incorporated into the shampoo base. The organic solvent thereafter helps disperse the styling polymer in the shampoo composition, and also helps enhance deposition of the styling polymer onto hair. The use of these solvents, however, can sometimes contribute undesirable odors to the finished product, or otherwise present formulation problems, e.g. compatibility with other materials in the shampoo composition.
To minimize the use of these organic solvents, latex polymers rather than dissolved polymers have been employed as a means of incorporating styling polymers into a shampoo composition. Latex polymer systems are stable dispersions, typically colloidal dispersions, of water insoluble polymer particles in a continuous aqueous phase. As such, there is little or no organic solvent to contribute undesirable odors or to otherwise present incompatibilities with other materials in the shampoo composition. Without the organic solvent, however, deposition of the latex particles onto hair, which is essential for allowing the styling polymer to set and form a film onto the surface of hair, can be problematic. Historically, styling polymers (both latex and dissolved polymers) for use in shampoos have been selected so as to have higher Tg values. It was believed that higher Tg polymers would form stiffer films on hair, thus providing improved styling performance. Latex polymers, however, with the higher Tg values often have poor deposition profiles thus making it desirable to add latex deposition aids, e.g., cationic polymers, or to increase the concentration of the latex polymer in the styling shampoo composition.
The foregoing considerations involving styling shampoo compositions and latex polymer systems indicates that there is a continuing need to identify latex polymer shampoos with improved latex deposition profiles and styling performance. Accordingly, it is an object of the present invention to provide such compositions, and further to provide such compositions that do not necessarily require the use of latex deposition aids, and further to provide such compositions with reduced or minimal levels of polymer latex to achieve the desired latex deposition profile and styling performance.